"Object Oriented Programming with PHP5" is a book that helps understanding many of the core OOP features within PHP, whilst looking at the Model-View-Controller (MVC) design pattern and unit testing.

Ryan comments of a few issues he found with the book include the not-quite-an-introduction-level first chapter and the "More OOP" section that read like a copy of the php.net manual. Overall, though, his opinion is that it's a good book and provides a good overview of database functionality and the MVC design pattern.